The present invention generally relates to equipment and procedures for use with health care patients. More particularly, the present invention encompasses methods and equipment for monitoring soft tissue pressure to which a patient may be subjected, with the intent of reducing the risk of soft tissue damage.
Pressure (decubitus) ulcers, commonly known as bedsores, present a serious problem to bedridden and wheelchair-confined patients. Prolonged pressure from a patient's body weight upon bony prominences is the most common cause of pressure ulcers. Prevention of and care for a preexisting pressure ulcer typically include treatment plans that involve relieving pressure on the exposed area by positioning and maintaining the patient off susceptible areas and any preexisting pressure ulcers, and minimizing localized pressure through the use of gel pads and similar types of products capable of absorbing and/or distributing pressure. However, such approaches can be insufficient if caregivers are unaware that a patient has shifted his/her weight onto prominences that are prone to pressure ulcers.
There are a wide variety of pressure sensors in the industrial and medical markets, some of which have found use in monitoring pressure ulcers. Notable examples include those that use air and fluid displacement techniques, as well as electromechanical analog devices. Many of these sensors are very portable and can be used to measure pressures at various locations of a patient at any point in time. There are also sheets of pressure sensors used primarily for research that give color-coded results from computer programs. The latter sensor type has been particularly used by manufacturers and some healthcare facilities to identify maximum tissue pressures under bed and wheelchair patients' skin areas. There are also a number of pressure monitoring devices, for example, the Oxford Pressure Monitor MKII with 12 Sensor system available from the Talley Group, Ltd., and the Pressure Alert system available from Cleveland Medical Devices, Inc.
U.S. Pat. No. 8,535,246 to Drennan et al. discloses a pressure monitoring system for warning a patient or caregiver that soft tissue pressure has exceeded some predetermined level that over time would warrant moving the patient to prevent or at least reduce a risk of soft tissue damage. The system entails the use of a pressure sensing unit that generates electrical outputs corresponding to soft tissue pressure sensed at a surface of the patient's body. In preferred embodiments, the system monitors the electrical outputs over a preselected time period and generates a cumulative output signal based on the electrical outputs and corresponding to whether or not the soft tissue pressure has exceeded a predetermined pressure level during the preselected time period. The system may generate audible and/or visual warnings if the cumulative output signal exceeds a predetermined cumulative threshold until the soft tissue pressure drops below the predetermined pressure level.
Although the Drennan et al. system provides many benefits, further improvements in pressure monitoring systems would be desirable.